Looks like Trimble is adding further pieces to the BIM jigsaw for what they have in mind with the announced acquisition of WinEstimator.

There is a good assessment of where things may be leading in this article from GFXSpeak, which says,

Construction-based BIM

'As we noted when Trimble acquired SketchUp from Google earlier this year, the company intends to be a leader in building information modeling software (BIM), but unlike other firms in BIM which start with design, Trimble approach BIM from the construction side of the operation. Incorporating WinEst into the mix will allow Trimble and its Meridian Systems subsidiary to extend the range of services it provides to contractors and building owners, and streamline the flow of construction cost data.'